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Dental Hypotheses - Volume:9 Issue: 1, Jan-Mar 2018

Dental Hypotheses
Volume:9 Issue: 1, Jan-Mar 2018

  • تاریخ انتشار: 1397/02/10
  • تعداد عناوین: 6
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  • Jafar Kolahi * Pages 1-2
  • Zahra Shirazi, Inger Kj, Aelig, R. * Pages 3-10
    Introduction
    The purpose of this study is to elucidate whether dentitions and craniofacial profiles are different in unilateral and bilateral maxillary canine ectopia.
    Materials And Methods
    Radiographic materials from 75 patients with non-syndromic palatally displaced maxillary canines were studied. Bilateral ectopia occurred in 37 patients and unilateral ectopia in 38 patients. Orthopantomograms were analyzed for dental deviation including taurodontic morphology, abnormal crown morphology, invaginations of the incisors and short root lengths. Skeletal morphology was studied cephalometrically according to Björk. Statistic analysis were included.
    Results
    Significant more females than males had palatally ectopic maxillary canines. Gender differences were not observed between the uni- and bilateral ectopia groups. Orthopantomograms: the occurrence of taurodontia was significantly higher in the bilateral group while invaginations were significantly higher in the unilateral group. Patients with palatally displaced maxillary canines had an increased occurrence of agenesis. Profile radiographs: in the unilateral group significantly retroclined maxillary incisors in females and males and a significantly posterior inclined maxilla in females occurred. In the bilateral group a significantly reduced slope of the maxillary incisors was demonstrated. Compared to the individuals without palatally displaced maxillary canines, the maxillary incisors were significantly retroclined in both groups.
    Conclusion
    The present paper indicates a difference in the dentition and craniofacial profile in palatal unilateral and palatal bilateral maxillary canine ectopia. It is presumed that the unilaterally displaced canines have a dental origin while the bilateral cases have a skeletal origin. If this is so, the diagnosis of the dental morphology (invagination and taurodontia) might help to distinguish between cases with dental etiology and cases with skeletal etiology. This distinguish may improve orthodontic treatment.
    Keywords: Canine, cefalometry, ectopia, human, orthpantomogram, profile radiographs
  • Maryam Khoroushi, Shahab Etemadi, Mitra Karbasi Kheir * Pages 11-15
    Introduction
    Marginal leakage is one of the significant causes of restoration failure. This in-vitro study was conducted to compare cone beam computed tomography (CBCT) and dye-penetration methods for determining marginal leakage at gingival surface of class V resin composite restorations.
    Materials And Methods
    Class V cavities were prepared on the buccal surfaces of nineteen caries-free extracted human molar teeth. Cavities were conditioned and filled. The teeth were immersed in a 50% w/w aqueous silver nitrate solution for 24 h and were taken out and rinsed with distilled water. Then, they were put into a developing solution. Whole specimens were first viewed with CBCT and were then sectioned and evaluated by stereomicroscope.
    Results
    Measurement of agreement between CBCT and stereomicroscope revealed that 15 (78.9%) teeth had score 0, 1 (5.3%) tooth had score 1, and 1 (5.3%) tooth had score 2 in both techniques. Measurement of agreement between CBCT and stereomicroscope techniques, in the detection of marginal leakage, was 89.5% (Kappa coefficient = 0.627, P = 0.00). The Wilcoxon paired rank test revealed no significant difference between the results of CBCT and stereomicroscope in measuring the leakage at gingival margin (P = 0.157).
    Conclusion
    Considering the limitations of the study, there was no significant difference between the results of CBCT and stereomicroscope in measuring the leakage at gingival margin of class V composite restorations. CBCT can be used noninvasively to detect the marginal leakage of gingival wall of class V composite restorations using aqueous silver nitrate solution as a tracer.
    Keywords: CBCT, composite resin, leakage, marginal, stereomicroscope
  • Mehrdad Abdinian, Atiehsadat Hashemian, Amir A. Sameti * Pages 16-19
    Introduction
    Magnification and distortion are the most important limitations of panoramic radiography. The aim of this study was to determine the effects of changing focal trough option of Planmeca SCARA 3 on the accuracy of linear distance measurements.
    Materials And Methods
    In this in-vitro study, 28 pieces of gutta-percha were attached to the assumptive place of each lost root of an adult dry skull with average size and normal shape. The actual measurements were obtained by a digital caliper. The panoramic images of the skull were taken in six different sizes and shapes of focal trough. This procedure was repeated ten times with new gutta-percha. Paired t-test was used to compare the values of different actual and radiographic images of gutta-percha dimensions.
    Results
    The mean difference [standard deviation (SD)] between actual measurement and panoramic radiography in the different groups was from 0.37 (1.1) to 0.58 (2.87) mm. The mean (SD) difference of linear measurements between real and radiographic images was 0.52 (0.43) mm in average size, V-shaped group, which was statistically and clinically significant (P = 0.00).
    Conclusion
    Changing the focal trough option of Planmeca SCARA 3 has minimal effects on the accuracy of linear measurements in panoramic radiographs.
    Keywords: Image distortion, magnification, panoramic
  • Shikha Sharma, Ashita S. Uppoor *, Srikant Natarajan Pages 20-24
    Introduction
    The global burden of dementia, diabetes, and periodontitis is rapidly increasing and is becoming a serious area of concern. The incidence of diabetes and periodontitis usually increases in middle age, and because they share a bidirectional relationship, they are known to worsen if not controlled. Evidence suggests that the people who have diabetes are at a significant risk of developing dementia and in the last two decades, periodontitis has been increasingly linked with dementia. Currently, there is no definitive treatment of dementia.
    The Hypothesis: The patients who have uncontrolled diabetes with moderate-to-severe periodontal disease may be at a greater risk for developing neurodegeneration associated with dementia.
    Evaluation of the Hypothesis: The chronic effects of both periodontitis and diabetes may have an uncontrollable additive effect on the body of an aging individual. Immunosenescence may add to the complexity of such effects and in such a scenario, the complete resolution of the systemic inflammation or other interrelated process responsible for directly or indirectly triggering neurodegeneration may be compromised. We have proposed various interrelated mechanisms linking diabetes and periodontitis that may be amplified in an aging individual. These mechanisms may contribute to the neurodegeneration associated with dementia. Oral cavity is a major unbarred window into the systemic environment of an individual. Treatment and maintenance therapy for periodontitis on a routine basis may help reduce a significant amount of inflammatory load, especially in the diabetic population, who are at a greater risk for the future development of dementia.
    Keywords: Dementia, diabetes, periodontitis
  • Kristian Havsed, Anna N. Helkimo, Inger Kj, Aelig, R. * Pages 25-28
    This case focuses on dental deviations in a girl now 14 years of age. It is questioned in the article if an accident caused by the girl’s fall into a cactus at the age 1 year and 2 months could possibly result in local dental disorders in the permanent dentition. The disorders were the short roots and small crowns. It is discussed in this paper if it is the pins from the cactus or the many medical and operative procedures for the removal of the pins that caused the disorders. Nine questions concerning etiology are raised and discussed and only partly answered. This case gives new information concerning the normal eruption and resorption processes. It demonstrates how the teeth without roots or with short roots can erupt normally and even earlier than the contralateral teeth. Furthermore, it is demonstrated that a second premolar with short root is able to resorb the overlying primary molar. In this dentition with severely malformed teeth, the treatment plan scheduled for the girl still takes into account these normal developmental conditions.
    Keywords: Anesthesia, cactus needle, radiographs, resorption, short roots, treatment plan